1. Field of the Invention
The present invention relates to an illumination apparatus usable in a liquid crystal projector and the like, and a projector provided with the illumination apparatus.
2. Related Background Art
In an optical system of a liquid crystal projector disclosed in Japanese Patent Application Laid-Open No. 10-148795, since shapes of pupils of light of red (R), green (G) and blue (B) are not the same, color unevenness occurs on its screen.
Further, in an optical system of a liquid crystal projector as disclosed in Japanese Patent Application Laid-Open No. 63-116123, since optical lengths are different among three colors of R, G and B, color unevenness occurs on its screen.
Furthermore, in an illumination apparatus using a high-pressure discharge lamp of a reflection-type light source, since heat is radiated through heat-resisting cement and a reflection mirror, temperature of a light radiation tube on its side fixed to the reflection mirror through the heat-resisting cement is lowered when an alternating current with symmetric positive and negative components is supplied to the high-pressure discharge lamp. Hence, color unevenness occurs in the lamp itself, and a case where color unevenness occurs on a screen may occur when such a lamp is used as a light source of a liquid crystal projector.